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SCOOT is a real-time traffic responsive control system whereby the
signal timings are continuously updated depending on the traffic demand,
as measured by numerous strategically placed inductive loops. Queues and
stops are predicted and then incremental timing changes are made on a
regular basis to minimise a performance index. The green time splits and
offsets between adjacent signals are updated every cycle and the cycle
time every 5 minutes.
SCOOT has an advatage over FIXED TIME control in that unforeseen
events, such as an accident or an extended peak (due to rain for
example) can be handled. SCOOT simply extends the peak period until the
demand ends. When traffic volumes are low, for example during school
holidays, there can be problems in that there is generally too much
spare green in the peak period fixed time plans. SCOOT on the otherhand
would maintain an optimal cycle time, hence greatly reducing delay and
fuel consumption.
SCOOT has been installed in several
cities in the UK and results of before / after studies show a road user
cost saving of approximately 12%.
Durban's SCOOT system was installed in the Point Road area and
commissioned in October 1991. A subsequent before / after study
conducted by the CSIR indicated road user savings as:
- Annual vehicle operating cost = + 3%
- Annual time costs = + 7%
The present system includes the following 8 nodes:
- Pine St / Brickhill Rd
- West St / Point Rd
- Smith St / Point Rd
- Point Rd / Keeler Pl
- Point St / Winder St
- Point Rd / Rutherford St
- Gillespie St / Rochester St
- Gillespie St / Rutherford St
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